ISBN 978-979-98300-1-2 Oil tanning practiced nowadays has some weaknesses, such as requires a long oxidation
time, i.e. nine days to two weeks [4, 5]. This causes overall production time becoming relatively long; thereby it reduces the efficiency of the process and directly affects the
production capacity of the leather industry. Our previous study has shown that the addition of hydrogen peroxide H
2
O
2
was able to accelerate the oxidation time of the production of chamois leather [6]. However,
currently the appropriate oxidation time for chamois leather using rubber seed oil and hydrogen peroxide has not been known. Appropriate oxidation time in the tanning is
necessary to improve efficiency of the process and quality of the leather, thus it will increase added value of the product. The objectives of this study were to investigate the
effect of oxidation time in the chamois tanning on the chamois leather quality and to determine the best condition of oxidation time for the tanning accelerated by hydrogen
peroxide.
2 Materials and Methods
2.1 Materials and Equipment
The materials used in this study were pickled goatskin, rubber seed oil, hydrogen peroxide, glutaraldehyde Relugan GT50, degreaser, formic acid, sodium carbonate, and
salt. The equipment used in the tanning were rotary drum, stacking, buffing machine, shaving machine, sammying machine, toggle dryer, and the horses. Physical testing
equipment used were thickness gauge, Kubelka glass apparatus, tensile strength tester UTM Instron, calliper, and scissors.
2.2 Methods
2.2.1 Tanning Tanning process consisted of pH adjustment, pretanning, fixation, aging, shaving,
washing, oil tanning, washing, toggling, drying, and buffing. The oil tanning was carried out by using a modified method of Suparno et al. [7]. The modifications were the
additions of oil diffusion process conducted in the rotary drum for 8 hours and oxidation processes inside the drum for 4, 6, and 8 hours. The inside rotary drum oxidation process
was undertaken by using hydrogen peroxide as oxidation agent with concentrations of 6 based on the weight of rubber seed oil used. The outside rotary drum hang on the toggle
dryer oxidation process was carried out for 1, 2, and 3 days. The tanning procedure is shown in Table 1.
2.2.2 Leather Testing Physical and orgnoleptic properties of chamois leathers were tested. Physical properties,
which were water absorption, tear strength, tensile strength, and elongation at break, were measured using SLTC methods [8]. Organoleptic properties, i.e. softness, colour and
odour, were tested by two chamois leather experts.
Oxidizing Agent
ISBN 978-979-98300-1-2
Table 1. Procedure of tanning using rubber seed oil modification from Suparno et al. [7]
Process Chemical Amount Duration
Remark pH
adjustment Water
200 Drum at 8 rpm
Measure pH at 3 and
o
Be at 8 NaCl 10
10 mins
Formic acid Pretanning
Relugan GT50 1.5
4 x 15 mins, then
1 h Dilute with water 3
times Drum at 12 rpm
Fixation Sodium formic
1 4 x 10
mins Dilute 20 times
Sodium carbonate
1 Measure pH at 8
Drain Aging
Overnight Cover with plastic
Shaving Shave both sides
Washing Water
1000 3 x 15
mins. Drain
Oil tanning Water
200 10 mins
Drum at 8 rpm Sodium
carbonate 0.5
Rubber seed oil 30
Leave overnight
Drum for 8 h Oxidation inside
the rotary drum 4, 6, and 8
hours Rotate in the drum
Oxidation outside the drum
1, 2, and 3 days
Hang on the tiggle drier at room
temperature Washing Sodium
carbonate 3
Stake Repeat 3 times
Degreaser 0.2 Water 300
Drain Toggling and
drying 1
day Buffing
Buff both sides
3 Results and Discussion
3.1 Water Absorption
Water absorption is the leather ability to absorb water per weight unit of leather and expressed in percentage. Water absorption is an important parameter in determining the
quality of chamois leather, as the main use of the leather is as a filtering, cleaning and drying agents that require high water absorption capacity. The higher water absorption of
the chamois leather, the better its quality.
ISBN 978-979-98300-1-2 Measurement of water absorption was carried out for the first 2 hours of water absorption
by the leather samples. This study shows that water absorptions were in the range of 291.4 - 357.6 Figure 1. In generall, the water absorption of the chamois leathers in
this study met the standard of SNI 06-1752-1990 [9], i.e. minimum of 100. Water absorption was affected significantly by oxidation time inside the rotary drum,
while oxidation time outside rotary drum and the interaction between those two factors did not significantly affect the value of water absorption. The highest water absorption
was obtained in the treatment with a combination of inside rotary drum oxidation time of 4 hours and outside rotary drum oxidation time of 2 days Figure 1.
Figure 1. The relationship between oxidation times inside and outside the rotary drum and the water absorption of chamois leather
The treatment of 4 hours inside the rotary drum oxidation time gave a significantly different effect on the oxidation time of 6 hours and 8 hours, whereas the treatment of 6
hours and 8 hours gave almost the same or not significant effect. Oxidation time of 4 hours gave the highest average value of water absorption, 344. This could be due to the
longer oxidation time in the drum can lead to oxidative reaction occurs more dominantly on the leather surface, so that when the leather is oxidized in the open air outside the
drum, oxygen from the air can not oxidize the oil in the deeper layer of the leather, because it was blocked by the oxidation products on the leather surface.
3.2 Tear Strength
